1. Field of the Invention
The invention is related to a resistive memory device with an air dielectric layer, and a method to fabricate the same.
2. Description of Related Art
As portable products rapidly develop and demands for functions increase, demands in the global memory market are rapidly expanding. In particular, the growth of non-volatile memories (NVM) has drawn the most attention. In order to deal with market changes, big factories and research facilities around the globe have begun development in next generation memory technologies. Among the many types of possible technologies, resistive random access memory (RRAM) is one of highly focused technologies.
In a resistive memory device, current heating effects are used to change a resistance value of a resistance switching material layer, and different resistance values represent different bit values. For example, a high resistance value represents 1, and a low resistance value represents 0.
In the resistive memory device, a metal oxide is generally used as the resistance switching material layer. Contact holes often exist near the resistance switching material layer. The contact holes are formed by a material such as silicon oxide or silicon nitride. However, during the process of fabricating the resistive memory device, the dielectric layer generates leakage currents due to the process, and the leakage currents damage the electrical characteristics of the resistance switching material layer. In addition, during the process of fabricating the resistive memory device, charges carried by a plasma which is used for etching or cleaning may also damage the electrical characteristics of the resistance switching material layer. As a result, an amount of change and a degree of uniformity in the resistance values when the resistive memory device is turned on or turned off are adversely affected.